Ask anyone in the oil business which company they admire the most, and 99 times out of 100 you will get the same answer: ExxonMobil. The technical excellence of its staff and the rigour of its corporate culture are res-pec-ted, envied and sometimes feared by competitors.

That discipline - a word often used in connection with Exxon, including by the company itself - has paid off handsomely for investors. Whether viewed over the past five years or past 20, Exxon's total shareholder returns have comfortably exceeded the average of its peers: Royal Dutch Shell, BP and Chevron.